Field of the Invention
The invention relates in general to a method for compensating the frequency dependent phase imbalance, and more particularly to a method for compensating the frequency dependent phase imbalance in a receiver or a transmitter.
Description of the Related Art
Radio frequency (RF) system is widely adopted in wireless communication. Although RF system has the advantages of low cost and low power consumption, one of its main problems is IQ imbalance. Part of the IQ imbalance results from the mismatch of amplitudes between in-phase (I) and quadrature (Q) paths and local oscillators, and the phase shift is not exactly 90 degrees. The mismatches of amplitude and phase shift are called gain and phase imbalance. Since the IQ imbalance degrades the system performance considerably, it is a critical issue as how to provide a method for the RF system to compensate the IQ imbalance and improve the system performance.